The concept of ubiquitous computing is used in computer science, software engineering and hardware engineering for computing which can take place in any format, any device and at any location, unlike desktop computing. The traditional view of computing systems has been irreversibly changed by the recent technical developments in hardware and software. They not only contain linked servers but also include a wide variety of embedded and pervasive devices, which lead to the development of ubiquitous computing systems. Cryptanalysis methodologies and tools are used to enhance the security of the ubiquitous computing environment, by providing protection and controlling access to data. Cryptanalysis is the process of examining information systems for understanding hidden aspects of the systems. It involves the study of theoretical and practical cryptographic mechanisms intended to provide privacy and security. This book unravels the recent studies on ubiquitous computing. It will elucidate the concepts and innovative models around security issues and threats in ubiquitous computing systems. The book will help the readers in keeping pace with the rapid changes in this field.